Horizontal gas/gas two-phase composite straight line reference method and apparatus based on gravity force balance

Abstract

A horizontal gas-gas two phase composite beeline benchmark method and a device based on the gravity balance belong to the technical field of precision instruments and measurement. The method comprises the steps: a balance slideway is constructed below of an orientation slideway, which forms an open external gas support and acts on an anti-thrust plate in the lower part of a flotation guide cover, the gravity balance of the orientation slideway and the balance slideway is designed aiming at the load gravity, under the conditions of satisfying the load gravity of the balance slideway, and the gas film supporting stiffness arrives the maximum or is in the confirmed range of the gas film supporting stiffness; the device comprises the anti-thrust plate fixedly connected with lower part of the flotation guide cover, an anti-thrust flotation dual surface is formed between the anti-thrust plate and the balance slideway, the anti-thrust plate is provided with a throttle structure facing to the balance slideway which is parallel to the orientation slideway. The invention leads the flotation guide cover to have excellent stability, the slideway load capability and the supporting stiffness are greatly improved, the high linear accuracy of the slideway under big load and big stroke is ensured, the structure is simple, and the application scope is wide.

Description

technical field [0001] The invention belongs to the technical field of precision instruments and measurement, and in particular relates to a horizontal gas / gas two-phase compound linear reference method and device based on gravity balance. Background technique [0002] With the rapid development of advanced manufacturing and measurement technology, more and more large-scale, precision processing equipment and measuring instruments are required to have a large stroke and high load capacity for horizontal linear datums used in high guiding accuracy . Although the traditional sliding friction guideway pair has a large load-carrying capacity, it has been gradually replaced by gas-lubricated guideway due to the defects of low guiding precision, poor motion sensitivity and easy crawling. At present, most of the horizontal linear datums commonly used in high-end instruments and equipment are hydrostatic gas-lubricated guide rails, but there are two problems in practical applicatio...

AI Technical Summary

Problems solved by technology

Although the traditional sliding friction guide rail pair has a large load-carrying capacity, it has been gradually replaced by gas-lubricated guide rails due to defects such as low guiding precision, poor motion sensitivity, and easy crawling.

At present, most of the horizontal linear datums commonly used in high-end instruments and equipment are hydrostatic gas-lubricated guide rails, but there are two problems in practical applications: First, the structure of the guide rail is a fixed beam structure at both ends, that is, the guide rail In the working state, it is in the state of fixed support at both ends and suspended in the middle. The load gravity all acts on the guide rail. When the guide rail is in a large span and high load, it is easy to cause the bending deformation of the guide rail ( figure 1 The dotted line in the middle shows the schematic diagram of the bending deformation of the guide rail), and this kind of deformation is mostly plastic deformation, which directly damages the working accuracy of the guide rail; second, because the gas viscosity is very small and the gas has compressible properties, the stiffness of the gas support in the vertical direction is relatively Small size, low load-carrying capacity, the thickness of the air film in the vertical direction decreases sharply when bearing an excessive load or impact, which can easily cause direct contact between the air bearing guide sleeve and the guide rail, resulting in "shaft holding" and serious damage Rail structure

These methods are to take some control measures on the guide rail structure to obtain higher stiffness or controllable stiffness, but their structures are very complicated, and the control and adjustment are also complicated; in addition, these methods have not solved the problem of large travel, large load or The Bending Deformation of the Beam of the Guide Rail under the Oversized Load

[0004] The new aerostatic guide rail using porous throttling proposed by the National University of Defense Technology, its basic principle is to use the microstructure of porous materials to throttling, and at the same time set shallow grooves on the surface of the guide rail that communicate with the porous throttling device. Using the impedance of the groove to form a secondary throttling can achieve the purpose of improving the stiffness and bearing capacity of the air guide rail, but this structure is easy to block, and also cannot solve the problem of bending deformation of the guide rail beam under large load and large stroke

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